Refrigerator air circulation control



J. B. TUCKER REFRIGERATOR AIR CIRCULATION CONTROL Jan. 13, 1953 Filed Dec. 12, 1950 Inventor: John B. Tu cke'r;

is Atb.

Patented Jan. 13, 1953 UNITED STATES PATENT OFFICE REFRIGERATOR AIR CIRCULATION CONTROL John B... Tucker, Marblehead; Mass assignor to General. Electric Company, a corporation. of

New York Application December 12, 1950, Serial No. 200,383-

6 Claims.

My invention. relates to refrigerators and more particularly to. arrangements for controlling air out with: particularity in the claims; annexed.

to and forming; a part of. this specification.

In carrying out the objects. of my invention, adamper is provided for controlling the circu-- lation of air through a; passage withinv the food. storage compartment of therefrigerator cabinet. The position of this damper is-controlled in. response to the temperature of the. refrigerating unit, and more-specifically thetemperature of the case of the motor-compressor assembly, so that I the: circulation of air is increased as a tem-- peratureof the case increases and vice versa.

For a better understanding of my invention, reference may be had to the accompanying. drawing in which Fig. 1. is a. side; elevation view, partly broken away, of the refrigerator cabinet incorporating an embodiment of my invention; Eigja'Z is an enlarged side. elevation view. of a portion of Fig; 1.; and Fig. 3 isan end; view of the. apparatus. shown in Fig. 2.

Referring now to the drawing, there is shown a refrigerator: cabinet I which includes an. outer wall and a spaced inner wall orliner 3 which defines a food storage compartment 4. The space between the innerand outer walls is filled: with asuitable heat-insulating material. 5" The access. opening of the storage compartment 4 is closed by a hinged door 6.

A, cooling unit or evaporator! is disposed in theiupper portion of the compartment t for cooling this compartment. Refrigerant is sup plied; to the. evaporator I: from an. refrigerating:

unit; 8.. disposed inv a machinery compartment 9* atv the bottom of the refrigerator... The refrigcrating. unit 8 is of the conventional type: well known in the art which includes a motor-compressor assembly (not shown) disposed within a hermetically-sealed case I'O;

The compartment 4 is refrigerated by air which moves by natural circulation over the evapo- 2v rator" I downwardly to; the bottom. of. the com-- partment 4- and then, as the air becomes warmed,

upwardly to the evaporator L A path for citculation. of air within, the food storage com:- partment. is: defined by a bafile: ll. This baiile- H is positioned. beneath the evaporator 1' and:

supported on a plurality of supportsi2 mounted on the liner 3.. As illustrated, thepbailie H extends: substantially to the rear wall of. the liner 3, an opening. l3 being provided in the rear portion of the baffle H defining a passage for:

circulation. of. air therethrough. Thus air circulating. within the'com-partment 4 passes. rearwardly between. the evaporator I and. the baflie H and then downwardly through. the opening: 13; Alternatively; of course, the baffle Hi: could be terminated at thev opening: l3: so that the wear end of the baflle. is itself spaced from the rear wall of the liner 3: to define an: air-circulating passage;

The refrigeration requirements" for maintain-- ing the compartment i at a proper temperature may varydependent upon a number of factors. For example, these requirements increase as the: ambient temperature increases andv tomaintain a proper operating temperature in the compartment 4 under the-conditionof' increased ambient temperature, it. is desirable. to increase the rate of air circulation oven the evaporator l and through'thecompartment' 4. Also the refrigeration; requirements increase substantially with increased load, for; example; that'attributable to an increased; number of. openings of the door 6. By my arrangement air circulation in the: compartment t is varied to compensate for these variations in ambient temperature and. in increased load. As the ambient temperature in.- creases or as an. increased load is placed on the refrigerator, for example by increased door openings, these increases are reflected in an in-- crease in the operating temperature of the refrigerating unit and, more specifically, in the temperature. of. the case I'll which surrounds and hermetically seals the mot1or-compressor assembly; Toeffect the aforementioned compensation, a damper I4 is provided; in thefood storage compartment, and this damper is controlled automatically in response: to the temperature of the refrigerating unit: 8.

The damper I4- is arranged for controlling flow of air through; the aforementioned passage sons to regulate this flow of air in accordancewith. the temperature of the refrigerating: unit 8' or, more specifically; with the temperature of the case ID of this refrigerating unit. The

damper I4 is pivoted at IS on a bracket [6 which is mounted on the liner 3. The damper is moved by a closed control system which includes a bellows IT, a temperature-responsive bulb or feeler l8 and a connecting tube l9. This closed control system is charged with a volatile fluid. The temperature-responsive bulb or feeler I8 is mounted on the case ID of the refrigerating unit in direct heat exchange relationship therewith. The bellows I1 is positioned within a recess in the insulation between. the spaced inner and outer walls of the refrigerator, being supported by studs 20 or other suitable supporting elements. The expansion of the bellows is opposed by a coil spring 2|. The compression of the spring 2| may be adjusted by a screw 22 accessible from the compartment 4 for properly calibrating the apparatus. The bellows I1 and the spring 2] bear against an arm or member 23 which is pivoted at 24. The free end of the arm 23 is connected by a pin 25 to a link 26. The other end of the link 26 is formed in a hook as indicated at 21 to engage a pin 28 on the damper I4. An L-shaped bracket 28a is provided to support the heatinsulating material to space it from the abovedescribed mechanism.

As the bellows l1 expands the arm 23 is moved by the bellows toward the dotted line position indicated in Fig. 2, swinging the damper l4 in a counterclockwise direction about its pivot l5 to increase the circulation of air through the opening I3. As the bellows contracts the spring 2| moves the arm 23 back toward its solid line position, thereby swinging the damper I 4 in a clockwise direction toward its solid line position, as illustrated in Fig. 2.

Under varying conditions of ambient temperature and under varying loads, the temperature of the refrigerating unit and, more specifically, the temperature of the case I 0 thereof, varies over a substantial range, and this wide range of the controlling function makes it possible to operate the damper without sensitive and expensive apparatus. Moreover, this wide swing in the controlling function makes a large quantity of energy available for actuating the damper. Finally, the utilization of the case temperature as a controlling function enables the control to compensate not only for ambient temperature changes but also for other variations such as changes in door opening load which increase the load on the refrigeratorand on the refrig-. crating unit.

The operation of the apparatus is as follows. Under conditions of low ambient temperature and relatively small load on the refrigerator, the temperature of the case ID will be at a low point in its range and the resultant contraction of the bellows I! may position the damper l4 substantially in engagement with the bafile II, as illustrated by the solid lines in Fig. 2, thereby substantially blocking the circulation of air within the compartment 4. As the ambient temperature increases or as the load on the refrigerator increases, for example by an increased number of door openings, the temperature of the case In rises, causing an expansion of the bellows IT. The linkage 23, 26 is thereby moved toward the dotted line position shown in Fig. 2, swinging the damper in a counterclockwise direction toward the dotted line position and affording an increasing amount of air circulation through the opening l3. This increased circulation of air over the cooling unit 1 and through the compartment 4 provides more effective cooling of the compartment 4 and enables the maintenance of a substantially constant temperature therein despite the aforementioned variation in the ambient temperature or in the load. The opposite shifting of the controlling apparatus occurs upon decrease in ambient temperature or decrease in load resulting in a decrease in the case temperature. This opposite movement results in a reduction in the amount of air circulating over the cooling unit and through the compartment 4, minimizing the danger of freezing fresh food stored within a compartment 4.

While I have shown and described a specific embodiment of my invention, I do not desire my invention to be limited to the particular construction shown and described and I intend, by the appended claims, to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A refrigerator including a refrigerating unit, a food storage compartment and a cooling unit for said compartment, means within said compartment defining a passage for air circulating over said cooling unit and through said compartment, means for controlling flow of air through said passage, and means responsive to the temperature of said refrigerating unit for controlling the position of said air controlling means.

2. A refrigerator including a refrigerating unit, a food storage compartment and a cooling unit for said compartment, means within said compartment defining a, passage for air circulating over said cooling unit and through said compartment, a damper for controlling flow of air through said passage, and means responsive to the temperature of said refrigerating unit for controlling the position of said damper.

3. A refrigerator including a refrigerating unit,

a food storage compartment and a cooling unit for said compartment, said refrigerating unit including a motor-compressor assembly positioned within a hermetically-sealed case, means within said compartment defining a, passage for air circulating over said cooling unit and through said compartment, a damper for controlling flow of air through said passage, and means responsive to'the temperature of said case for controlling theposition of said damper. v

4. A refrigerator including a refrigerating unit,-

a liner defining a food storage compartment and a cooling unit for said compartment, a baflie within said food storage compartment below said cooling unit and spaced from a wall of said liner to provide a passage for air circulating over said cooling unit and through said compartment, a damper positioned adjacent said wall of said liner for controlling flow of air through said passage, and means responsive to the temperature of said refrigerating unit for controlling the position of said damper.

5. A refrigerator including a refrigerating unit, a liner defining a food storage compartment and a cooling unit for said compartment, a baflle within said food storage compartment below said cooling unit, said bafile having an opening therein for air circulating over said cooling unit and through said compartment, a damper for controlling flow of air through said opening, and means responsive to the temperature of said refrigerating unit for controlling the position of said damper.

6. A refrigerator including a refrigerating unit.

a food storage compartment and a cooling unit for said compartment, said refrigerating unit comprising a motor-compressor assembly disposed within a hermetical1y-sealed case, means within said compartment defining a passage for air circulating over said cooling unit and through said compartment, a damper for controlling flow of air through said passage, 2. bellows for positioning said damper, a spring opposing said bellows, and a closed control system including said bellows and a temperature-responsive feeler connected thereto, said system having a volatile fluid therein, said feeler being mounted on said case in heat exchange relationship therewith whereby increase in temperature of said case causes expansion of said bellows to move said damper for increasing air circulation through said passage.

JOHN B. TUCKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

